HI ALL. I,m new here so bare with me. I have a small problem. I have been using a sport air filter on my 97 528 for about a year now. I wanted to put the original filter housing with the original filter back on. I put the thing back on and started the car. All of a sudden my car started putting and turning off. No power in first gear. I took the original back off and put the sport filter back on, still putting. I disconnect the four pin connector thats connect to the air fliter intake now it runs good. Why is this? All i did was change filters and the car. Could anybody tell me. Maybe the ecu compenstaed for the dirty air filter and now its runnign super rich?????